Criticality Potential of Waste Packages Affected by Igneous Intrusion

The objective of this calculation is to evaluate the criticality potential for co-disposal waste packages affected by an igneous intrusion disruptive event in the emplacement drifts. The scope of this calculation is limited to U.S. Department of Energy (DOE) Spent Nuclear Fuel (SNF) types in DOE standardized SNF canisters or Multi-Canister Overpack (MCO) Canisters. DOE SNF has been categorized into nine fuel groups for purposes of evaluating criticality safety (DOE 2004, [DIRS 170071], Table A-1).Sections 7.1 through 7.9 present the results of parametric evaluations for intact configurations and degraded configurations for the codisposal of DOE SNF. All outputs are reasonable based on the inputs, and the results of this calculation are suitable for their intended use. The results of this calculation are appropriate given the inputs and representations presented throughout this analysis. Variations in geometrical representation and material dimensions and compositions are not considered in this analysis nor are they bounded by the results of this analysis, unless demonstrated. Based on the results of this calculation and the critical limit in Attachment I, it is concluded that the keff value of the waste package is less than the critical limit during and after an igneous intrusion event for all DOE SNF designs.